Something

SELECT	category.description as CategoryDescription, product.productid, product.description as ProductDescription, 
			invoicedetail.quantity as quantityonhand, invoicedetail.price as salesprice 
					
	from		invoicedetail inner join product on invoicedetail.productid = product.productid
				inner join category  on product.categoryid = category.categoryid

	order by	category.description asc, product.description asc